Clamping device



' April 2 1943- P. MORGAN 2,317,690

CLAMPING DEVICE Filed Aug. 3, 1940 v 2 Sheets-Sheet l INVENTOR. PORTER ano/m/v ATTORNEY.

Ap 27, 1943. PQs. MORGAN CLAMPING nEucE Filed Aug. 5, 1940 2 Sheets-Sheet 2 FIG.9.

I INVENTOR. PORTER-3. Mom/V ATTORNEY.

Patented Apr. 27, 1943 CLAIVIPING DEVICE Porter S. Morgan, Weston, Conn., assignor to The Capewell Manufacturing Company, Hartford, Conn., a corporation of Connecticut Application August 3, 1940, Serial No. 350,937

11 Claims.

This invention has particular reference to monkey wrenches and, for convenience, is described as applied to such a device. But its prinfciples are applicable to a wide variety of tools which have fixed and movable jaws, for example, Vises and clamps, as will be apparent to those skilled in the art.

One object of the invention is to provide a construction in which the movable jaw may be se curely held in clam-ping position by friction means which may b quickly and easily released, when desired, so as to shift the position of th movable jaw.

Another object is to provide a construction in which the movable jaw may be quickly and freely moved to approximate clamping position and then, upon application of force to the wrench handle in the customary manner of using the wrench, this jaw will be held securely in clamping position.

Further objects will be apparent from the following description taken in conjunction with the drawings in which:

Fig. 1 is a longitudinal side View, partly in cross-section, of a monkey wrench embodying one form of the present invention.

Fig, 2 is a cross-sectional view taken on the line 2-2 of Fig. 1,

Figs. 3 and 4 are side and top views, respectively, of the wedge,

Figs. 5 and 6 are side and top views, respectively, of the intermediate friction member,

Figs. 7 and 8 are side and top views, respectively, of the retaining member, I

Fig. 9 is a longitudinal side view, partly in cross-section, of a slightly different form of monkey wrench embodying another modification of the invention,

Fig. 10 is a front view thereof,

Figs. 11 and 12 are cross-sectional views taken on the lines I I--II and I2i2, respectively, of Fig. 9, and

Fig. 13 is a perspective view of one of the interfitting friction members. I

Referring first to the embodiment shown in Figs. 1-8, inclusive, the fixed, or upper, jaw I is secured to the end of the shank 2 which has a handle 3 at the other end, and the movable, or lower, jaw 4 is slidable on the shank 2, as in the usual arrangement,

The movable jaw I has a longitudinal opening 5 therein adjacent the shank 2 into which two substantially L-shaped friction members I5 and I are inserted. The toes of these members. 8 and 9, respectively, extend into a suitable reces's'IIl in the upper part of the handle 3. A leaf spring II secured to the handle as shown prevents the friction member 1 from moving lengthwise of the shank and the toe 9 resting on the toe 8 prevents the friction member 6 from having such movement.

The retaining member I2, illustrated in Figs. 8 and 9, is inserted in the enlarged opening in the lower part of the movable jaw and the friction members 6 and 1 pass through openings in the upper and lower branches of this member so that it is free to slide lengthwise of these friction members. As will be seen from Figs. 1 and 2, the vertical, channel-shaped portion of the member I 2 is adapted to slide in contact with the edge of the shank 2. This retaining member is provided with two rollers I3 carried by a pin I4 supported in the ends of the lower branch of the retaining member. This pin is free to turn in an elongated slot I5, sloping upwardly to the right as illustrated in Fig, 1.

The intermediat friction member I6, illustrated in Figs. 5 and 6, is L-shaped and fits snug-1 ly between the upper and lower branches of the Its vertical leg is posl-' retaining member I2. tioned between, and adapted to be engaged on either side by, the friction members 6 and I,

as clearly shown in Fig. 2. Its horizontal leg has an opening I! through which the friction member I6 passes.

The wedge member I8, shown in Figs. 3 and 4, positioned between the upper branch of the retaining member and the toe of the intermediate friction member IB, has a channelled-shaped edge which slides in contact with the friction member fi, as illustrated in Fig. 2. Its inclined edge is adapted to engage a complementary inclined surface on the inside of the movable jaw 4. The assembly consisting of the wedge, the intermediate friction member and the retaining member, is kept in operating position in the movable jaw by means of th pin I9, driven or screwed into this jaw and passing into a su table groove 20 in the wedge. This groove is slightly wider than the pin so as to permit some relative movement between the movable jaw and the Wedge member, 7

To use a monkey wrench containing the present invention as above described, the movable jaw may be slid along the shank 2 until it contacts the surface of the nut or' other object to be held. Then on applying the usual turning force to the handle the lower jaw tending to open it. However, any

movement of the lower jaw under the action of c 3, pressure will be directed against v such pressure will cause it to move relatively to the wedge member l8. As will be readily understood, such movement will urge the wedge to the right, as shown in Fig. 1, so that its channel-shaped vertical surface will bear against the friction member 6. The latter in turn will exert pressure against the intermediate friction member [6 which exerts pressure against friction member 1. The latter, being in engagement with the channelled vertical leg of the retaining member l2 will cause it to exert pressure against the shank 2. movement of the movable jaw results in the application of considerable friction over a multiplicity of surfaces. It will be readily understood by those skilled in the art that the angle of the wedge may b so selected and the areas of the Thus it will be seen that a slight frictional surfaces so multiplied that suflicient resistance to the movement of the jaw 4 maybe,

obtained.

The movable jaw maybe released very easily through the action of the rollers 13 carried by the retaining member 12. Thus when pressure is exerted against these rollers so as to force the pin 14 which carries them upwardly to the right, as shown in Fig. 1, rotation of the rollers will result in a camming action against the lower surface of the movable jaw. Consequently the retaining member and the wedge carried by it will be caused to move downwardly with respect to the lower jaw, thereby releasing the pressure on the multiple friction surfaces and allowing the movable jaw to slide freely.

The embodiment shown in Figs. 9-13, inclusive,

- is particularly adapted to wrenches to be made from metal stampings. The stationary member from which the fixedjaw 3B, shank 3|, and handle 32 are formed, may be bent from a flat sheet into the cross-section shown in Fig. 12 and a filler piece 33 inserted between thesides and riveted or otherwise fastened therein so as to provide a'jaw of suitable width. In like manner, the movable jaw 34 may be madefrom a sheet bent into the form shown in Fig. 11 and provided with a filler piece 35 for the same reason.

The shank 3| has a recess 35 in which two friction members 31 and 38 are located, being held in position by a spring 39. Four interfitting members 40, one of which is illustrated in Fig. 13, are slidably mounted on these friction members. The extreme right hand member shown in Fig. 9 slides against the wall of the recess 36 in the shank, as illustrated.

A wedge member 4| is also inserted in the lower jaw and has one vertical edge which'is so configured as to engage the adjacent slidable member 40. An inclined surface 42 is provided on the opposite edge andis adapted to be engaged by a half round member 43 carried by the lower jaw. The member 43 is free to move in the lower jaw 34 so that even if the latter be tipped slightly in holding the work, the member t3 may cooperate properly with the wedge member 42. This wedge member is normally urged upwardly in the movable jaw by a spring 44. Another spring 45 projecting from the wedge member supports the extreme right hand slidable member 40 which by its engagement with the other slidable members, supports them.

To use a wrench containing this embodiment of the invention, the movable jaw 34 is brought into approximate clamping position against the work or object to be held. Upon applying the usual turning force through the handle 32, the reaction tending to force the movable jaw away from the fixed jaw brings into action the wedging effect which, as previously explained, results in the creation of multiple friction forces along the friction members 31 and 38 and the inside wall of the shank, sufficient to overcome further opening movement of the movable jaw.

The movable jaw may be released by applying pressure on the rounded projection 46 at the lower end of the wedge member which causes this member to be moved slightly away from the lower jaw against the action of the spring 44. This movement diminishes the wedge action and thereby reduces the multiple friction effect to such an extent that the movable jaw can be readily moved along the shank.

A wrench constructed acording to my invention is securely locked by means of friction against opening of the jaws until the wedge member is withdrawn to allow the movable jaw to slide. Furthermore, the greater the force applied to force-the jaws open, the greater will be the holding force to prevent opening. For example, if a force is applied in the direction of the handle on the movable jaw of the wrench shown in Fig. 1, the pressure or force tending to squeeze the wedge member I8, friction members 6, 1 and I6 and retaining member I2 together will be a function of the cotangent of the angle of the inclined wedging surfaces. But if this angle is too small, these Wedging surfaces will become locked together preventing or making it very difficult to Withdraw the wedge member and open the jaws of the Wrench after a substantial force has been applied to the movable jaw.

If the wedging angle is sufficiently large, for example an angle of 14-15 having a natural'cotangent of 4, and an opening force of pounds is applied to the movable jaw, the force tending to squeeze the friction members together will be 400 pounds. Now assuming that the frictionsurfaces have a coefficient of friction of 0.05 in order to provide easy adjustment of the movable jaw, the force tending to resist opening of the movable jaw at any one friction surface will be .05 400 or 20 pounds. By providing six or more friction surfaces, therefore, the total holding force will always exceed the opening force applied on the jaw-by 20% or more. By providing a sufficient number of friction surfaces for the wedging angle employed and the coefficient of friction between the friction members, I provide a device which is easily and smoothly adjusted and which holds securely when force is applied to the jaws in any position of the movable jaws.

It will be apparent that the same principle may be applied to Vises, clamps and other devices to furnish easy adjustability in one direction together with a secure gripping action when force is applied in the other direction to a movable jaw or other member.

It will be readily understood by those skilled in the art that various changes may be made in the forms and arrangements of parts described above without departing from the spirit and scope of the invention as set forth in the following claims.

. I claim:

1. A clamping device comprising a shank provided with a fixed jaw, a movable jaw slidable along said shank, and means for holding the movable jaw in clamping position on said shank, said means including a wedge member and a plurality of clamping members, a plurality of stationary members extending parallel to said shank, said wedge and clamping members being movable with said movable jaw, said wedge member reacting against said movable jaw to clamp said clamping members against one of said stationary members and said shank when the movable jaw is moved relative to said wedge member in a direction away from the fixed jaw and means for moving said wedge member relative to said movable jaw to release such clamping action.

2. A clamping device comprising a shank provided with a fixed jaw, a movable jaw slidable along said shank, and means for holding the movable jaw in clamping position on said shank, said means including a wedge member and a plurality of clamping members, a plurality of sta tionary members extending parallel to said shank and arranged alternately with said clamping members, said wedge and clamping members being movable with said movable jaw, said wedge member reacting against said movable jaw to clamp said clamping members against said stationary members and said shank when the movable jaw is moved relative to said wedge member in a direction away from the fixed jaw, means for holding said wedge and clamping members in the movable jaw, and means for moving said wedge member relative to said movable jaw to release such clamping action. I

3. A clamping device comprising a fixed jaw, a movable jaw, means for sliding said movable jaw into different positions relative to said fixed jaw comprising a plurality of fixed members with friction surfaces extending parallel to the direction of movement of the movable jaw and a plurality of clamping members movable with said movable jaw and having multiple surfaces in sliding contact with the friction surfaces of said fixed members, and wedge means actuated by movement of said movable jaw away from said fixed jaw to react against the movable jaw and clamp said clamping members in frictional engagement with said fixed members.

4. A clamping device comprising a fixed jaw, a movable jaw, means for sliding said movable jaw into different positions relative to said fixed jaw comprising a plurality of fixed members extending in the direction of movement of the movable jaw and a plurality of clamping members movable with said movable jaw and disposed between said fixed members with multiple surfaces in sliding contact therewith, and wedge means actuated by movement of said movable jaw away from said fixed jaw to react against said movable jaw and clamp said clamping members in frictional engagement with said fixed members.

5. A clamping device comprising a fixed jaw, a movable jaw, means for sliding said movable jaw into different positions relative to said fixed jaw comprising a plurality of fixed members extending in the direction of movement of the movable jaw and a plurality of clamping members movable with said movable jaw and having said fixed members disposed therebetween in sliding contact therewith, said members having smooth friction surfaces all of which are substantially parallel to each other, and wedge means actuated by movement of said movable jaw away from said fixed jaw to react against said movable jaw and clamp said clamping members in frictional engagement with said fixed members.

6. A clamping device comprising a fixed jaw, a movable jaw, means for sliding said movable jaw into different positions relative to said fixed jaw comprising a plurality of alternating fixed and movable clamping members having smooth surfaces extending in a direction parallel to the path of movement of the movable jaw in frictional engagement with each other, said fixed members being connected to said fixed jaw and said movable members being movable with said movable jaw, and a wedge tapered toward the fixed jaw and actuated by movement of the movable jaw away from the fixed jaw to clamp said clamping members together.

7. A monkey wrench comprising a shank carrying a fixed jaw, a movable jaw slidable along said shank, a friction member spaced from and held substantially parallel to said shank, a second friction member carried by said movable jaw arranged to slide between said first mentioned friction member and said shank, and a wedge tapered toward the fixed jaw and reacting against the movable jaw to press together laterally said friction members and shank when opening pressure is applied to said jaws.

8. A monkey wrench comprising a shank carrying a fixed jaw, a movable jaw slidable along said shank, a friction member spaced from and held substantially parallel to said shank, a second friction member carried by said movable jaw arranged to slide between said first mentioned friction member and said shank, a wedge tapered toward the fixed jaw and reacting against the movable jaw to press together laterally said friction members and shank when opening pressure is applied to said jaws, and means for releasing said wedge to open said jaws.

9. A monkey wrench comprising a shank carrying a fixed jaw, a movable jaw slidable along said shank, a plurality of relatively fixed friction members spaced from each other and from the shank, a plurality of sliding friction members carried by said movable jaw and disposed between fixed friction members and between one of said fixed friction members and said shank, and a wedge tapered toward the fixed jaw and reacting against the movable jaw to press together laterally said friction members and shank upon the application of pressure tending to open said jaws.

10. In a monkey wrench comprising a fixed jaw connected to a shank and a movable jaw, means for clamping said movable jaw in any adjusted position comprising a plurality of relatively fixed members connected to said shank, interfitting friction members between said fixed members and shank carried by said movable jaw in sliding engagement therewith, and a wedge member tapered toward the fixed jaw and arranged to react against said movable jaw and force said shank, fixed members and friction members into frictional engagement with each other upon movement of the movable jaw away from the fixed jaw.

11. In a clamping device having a shank provided with a fixed jaw, and a movable jaw slidable along the shank, means .for holding the movable jaw automatically in fixed position when opening pressure is applied on said jaws comprising a stationary clamping member extending parallel to said shank, a clamping member movable with said movable jaw and disposed parallel to and between said fixed member and shank, and wedge means disposed to react against said movable jaw and force said clamping members and shank together in tight frictional engagement when opening pressure is applied to said movable jaw.

PORTER S. MORGAN,

CERTI FI CATE OF c ORRECTION. Patent No. 2,317,690. X April 27, 1915.

PORTER s. MORGAN.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 514., for "jaws" second occurrence, read -jaw page5,first column, line 5, claim 1, after the word "against" strike out "one of"; and that the said Letters Patent should be read with this correction therein that the same may conf 01m to the record of the case in the Patent Office. Signed and sealed this 15th day of June, A. D. 1915.

Henry van Arsdale, (Seal) Actingvcommissioner oi Patents. 

